Applies To
Product(s):	AutoPIPE
Version(s):	ALL;
Environment:	N/A
Area:
Original Author:	Bentley Technical Support Group
Date Logged & Current Version	June. 2017 11.00.00.22

Problem:

How to calculate the soil properties for a buried pipe on a 45 deg angled slope from the horizontal plane?

Solution:

Most soil stiffness calculations in AutoPIPE are for based on piping oriented on the horizontal plane or vertical plane. Because of the unknown variation in a specific soil it is important to consider both a High soil stiffness and a Low soil stiffness in your Static Analysis.  

For a conservative approach for sections of piping on a 45 deg slope to the horizontal plane, suggest calculating both Horizontal and Vertical soil stiffness equations. Then compare the results for each equation and use the 2 extreme values (i.e. high and low soil properties) in your analysis.

Another approach would be to again calculate the Horizontal and Vertical soil stiffness equations. This time instead of using the highest / lowest values, take the average values of the results in the analysis. Once more creating a series of High soil stiffness values and low stiffness values. 

For your information, recall that soil springs stiffness values act perpendicular to the to the centerline of pipe

See Also

Model Soil Properties with Soil Calculator and Underground Piping

Bentley AutoPIPE